Shedding and extensive and prolonged environmental contamination of goat farms of Q fever patients by Coxiella burnetii

BACKGROUND: A majority (>70%) of Q fever patients in South Korea do not have a history of animal contact. Therefore, unconscious environmental exposure is suspected. The aim of this study was to investigate exposure of Q fever patients to environmental contamination and animal shedding. METHODS: Two goat farmers were enrolled. One was diagnosed with Q fever 3 years ago (Farm 1). Among 20 goats on Farm 1, five were tested randomly and found to be Q fever PCR‐positive. Three of the five were Q fever ELISA‐positive. Two of five environmental samples taken in 2015 were PCR‐positive. In 2018, 17 of 18 environmental samples were PCR‐positive. On Farm 2, 54 of the 77 goats were PCR‐positive, and 63 were ELISA‐positive. Twelve of 14 environmental samples were PCR‐positive. Repeat administration of oxytetracycline to goats led to a gradual reduction in PCR‐positive tests over a 5‐month period. However, PCR‐positivity of the farm environment persisted for 5 months. CONCLUSION: The environment on farms owned by Q fever patients was contaminated extensively and persistently, even after antibiotic treatment of goats and environmental decontamination. Undetected environmental contamination can be a major source of sporadic Q fever infection in South Korea.